The most surprising thing about "Her," the new Spike Jonze movie, is not that it dares to suggest an otherwise sane person might fall in love with the operating system that runs his computer and his smartphone. Or that middle-aged men look good in high-waisted pants. Or that it will be possible someday soon to ride a subway from downtown Los Angeles to the beach.

It is something simpler: that the near future is more interesting, culturally and architecturally, than the recent past.

Thanks to the digital revolution of the last two decades, it has become remarkably easy for filmmakers — and for songwriters, architects, novelists and car designers — to dip into a bottomless back catalog and borrow or remix work from the past.

This hasn't just produced a rampant anachronism in popular culture, with artists of all kinds churning through what the British music critic Simon Reynolds has called "Retromania." It has also made the future a lonelier and less appealing place.

There have still been movies imagining life 50 or 100 years from now, of course, during this period of wide-ranging cultural nostalgia. But they've tended to portray violent dystopias or post-apocalyptic wastelands. And star Tom Cruise.

And increasingly they have been pushed aside in the cultural conversation by films and TV series — "Computer Chess," "The Way Way Back," "Downton Abbey," "Mad Men," "Inside Llewyn Davis" — that either re-create an entire historic era with detailed ease or seem to exist in a nimble time machine, mixing elements of past and present the way a Spotify user can jump from Lorde to KRS-One and back again.

"Her" bucks the retro moment by jumping enthusiastically, and blindly, into a future that is neither utopian nor dystopian but — like our own era, and like every era —somewhere in the slippery in-between. The film is set in the Los Angeles of two or three decades from now; the year is never specified.

The city has dense clusters of tall towers and a mass-transit system to rival London's. Cars seem to have been banished. The thoughtful but hopelessly needy hero, Theodore Twombly, lives in a large and serene apartment in a downtown high-rise and either walks or takes the train everywhere.

The sidewalks and the rail stations are crowded with people. It's as if a benevolent Robert Moses, a planning dictator with a green agenda, had taken over the political realm in Los Angeles.

To create this colorfully remade L.A., Jonze and his production designer, K.K. Barrett, digitally plumped up the city's existing skyline. Jonze spoke at some length as he was preparing the movie with the New York architect Elizabeth Diller, whose firm is designing Eli Broad's new contemporary art museum in downtown Los Angeles.

The filmmakers also shot a number of scenes in Shanghai's Pudong district, which not only has an impressive collection of new skyscrapers but is laced with pedestrian sky bridges that allowed Jonze to film his actors without worrying whether the cars in the background looked futuristic enough.

The double setting also highlights the movie's interest in themes connected to surrogacy: to one person or thing standing in for another.

The operating system, called Samantha, stands in for the real girlfriend Theodore can't seem to find after his divorce. A young woman stands in for Samantha in what turns out to be a disastrous attempt at sexual intimacy between man and software.

Theodore stands in for the people who hire him, in his job at the candy-colored offices of a company called BeautifulHandwrittenLetters.com, to ghost-write personal notes to friends and relatives. In the same way, Shanghai stands in for the future Los Angeles.

Surrogacy, of course, is a basic ingredient of moviemaking. Actors stand in for characters made up by screenwriters. The action captured on film stands in for real life.

And Los Angeles has always stood in on-screen for other cities. The generic quality of its downtown streets in particular has made it attractive to directors of feature films and car commercials alike.

But another city standing in for the Los Angeles of the future? That's new, or at least extremely rare. And Jonze doesn't just do it simply because Shanghai looks more believably dense and developed than present-day Los Angeles.

Filming in Shanghai also allows him to capture something significant about the character, and the anxieties, of contemporary L.A. This is a city caught in limbo between two very different kinds of urbanism: between its private and car-dominated past and denser, more public and more connected future.

Clearly we are heading toward a Los Angeles with more and taller skyscrapers, livelier sidewalks and better public transit. But the process of building a mature rail system has a long way to go; we still love our cars. We're trying to put the private L.A. in the past but haven't quite reached the future many of us are hoping for and working to create.

Alternating between scenes shot in Los Angeles and Shanghai gives this limbo cinematic form. The city is stuck between two realms just like Theodore, with his feet on the ground in Los Angeles and his mind and heart in a digital reverie.

Those gestures by Jonze and Barrett turn "Her" into an extended and surprisingly kindhearted meditation on how we grapple with major change — personal, cultural, technological and architectural.

The reason the culture has become creatively stuck, endlessly reusing our own recent past, is not only that it has become so easy for artists and consumers to call up old material. It is also because we are in the midst of a dramatic and profound digital upheaval that is remaking our personal and professional lives.

We have had a tough time moving forward in part because we haven't had a chance to make any coherent sense of what this digital revolution means culturally.

The question seems so huge and unwieldy, so existential, that it has been easier to turn our backs and find either comfort and inspiration in the newly accessible past.

This retro turn hardly kills creativity; it has produced some energetic and important work, a lot of which seems to fully inhabit and animate past styles rather than simply ape them. This is particularly true of records and novels by artists in their 20s and early 30s, digital natives who effortlessly give fresh energy to discarded or antique genres.

Think of "Days Are Gone," the addictive 2013 debut from three twentysomething sisters from the San Fernando Valley in the band Haim, which shamelessly borrows tricks from '80s pop and still manages to sound fresh. Or "The Luminaries," the Booker Prize-winning novel by Eleanor Catton, a 28-year-old New Zealand writer who mines Victorian fiction for inspiration.

In architecture, too, the ease of looking backward has made looking forward tougher or simply more rare. Younger architects are relying on historic pastiche to a degree not seen since the heyday of postmodernism in the 1980s. Consider the work of the recently disbanded London firm FAT (Fashion Architecture Taste), which in recent years rescued tongue-in-cheek historicism from the margins of architectural practice.

Or the newly opened Ace Hotel on Broadway in downtown Los Angeles; occupying the ornate 1927 United Artists tower by the firm Walker & Eisen, the hotel has interiors remade by the Los Angeles design firm Commune as a loving tribute to 1920s architecture, with nods to Rudolph Schindler, Frank Lloyd Wright and the Viennese modernist Adolf Loos.

Like "The Way Way Back," which is essentially set in the 1980s and the present day at the same time, the hotel's design scheme is comfortable mixing historical eras: Layered atop the throwback architectural details are artworks by contemporary L.A. artists, including pencil drawings on the walls by the Haas Brothers.

At a certain point, though, we are going to have to confront the growing gap between the relentless pace of innovation in the high-tech world and the ever-faster cycle of rehash and rediscovery that dominates the cultural one.

"Her" is one of the first high-profile efforts to do so. Jonze sidesteps the retro riptide that has trapped so many of his peers. And he eagerly takes on the question of what it might mean to live in an era when nearly everything is capable of being delivered (and theoretically improved) in digital form — not just newspapers, music, novels and architectural blueprints but love affairs too.